An encroachment or intrusion.

Roget 716: attack; assault, assault and battery; onset, onslaught, charge.    aggression, offense; incursion, inroad, invasion; irruption; outbreak; estrapade^†, ruade^†; coupe de main, sally, sortie, camisade^†, raid, foray; run at, run against; dead set at.    storm, storming; boarding, escalade^†; siege, investment, obsession^†, bombardment, cannonade.    fire, volley; platoon fire, file fire; fusillade; sharpshooting, broadside; raking fire, cross fire; volley of grapeshot, whiff of the grape, feu d'enfer [Fr.].    cut, thrust, lunge, pass, passado^†, carte and tierce [Fr.], home thrust; coupe de bec [Fr.]; kick, punch etc. (impulse) 276.    battue^†, razzia^†, Jacquerie, dragonnade^†; devastation etc. 162; eboulement [Fr.].    assailant, aggressor, invader.    base of operations, point of attack; echelon.    ... show more

Roget 294: ingress; entrance, entry; introgression; influx, intrusion, inroad, incursion, invasion, irruption; ingression; penetration, interpenetration; illapse^†, import, infiltration; immigration; admission etc. (reception) 296; insinuation etc. (interjacence) 228^†; insertion etc. 300.    inlet; way in; mouth, door, etc. (opening) 260; barway^†; path etc. (way) 627; conduit etc. 350; immigrant.    ... show more

Roget 659: deterioration, debasement; wane, ebb; recession etc. 287; retrogradation etc. 283^†; decrease etc. 36.    degeneracy, degeneration, degenerateness; degradation; depravation, depravement; devolution; depravity etc. 945; demoralization, retrogression; masochism.    impairment, inquination^†, injury, damage, loss, detriment, delaceration^†, outrage, havoc, inroad, ravage, scath^†; perversion, prostitution, vitiation, discoloration, oxidation, pollution, defoedation^†, poisoning, venenation^†, leaven, contamination, canker, corruption, adulteration, alloy.    decline, declension, declination; decadence, decadency^†; falling off etc. v.; caducity^†, decrepitude.    decay, dilapidation, ravages of time, wear and tear; corrosion, erosion; moldiness, rottenness; moth and rust, dry rot, blight, marasmus^†, atrophy, collapse; disorganization; delabrement etc. (destruction). 162; aphid, Aphis, plant louse, puceron^†; vinefretter^†, vinegrub^†.    wreck, mere wreck, honeycomb, magni nominis umbra [Lat.]; jade, plug, rackabones [U.S.], skate [U.S.]; tackey^†, tacky [U.S.].    ... show more

An invasion or hostile attack.